Apparatus for moving elongated objects

ABSTRACT

Delicate elongated objects such as thin-walled tubing are moved, i.e., withdrawn from processing equipment by means of coneyor belts frictionally engaging such an object whereby additional low pressure means suck the objects against the belts. These belts have perforations and low pressure is applied to the back of the belts for suction through these perforations, but they are covered outside of the back belt suction area. The belts are provided with soft, profiled ridges, flanking the perforations to provide for a groove along which the object is sucked into engagement with the ridges.

United States Patent Vogts Oct. 28, 1975 APPARATUS FOR MOVING ELONGATED2,816,160 12/1957 Young 198/184 x OBJECTS 3,228,682 l/1966 Buccicone271/197 3,529,713 9/1970 Poupin 198/165 Inventor: Arnold g Krahenwinkel,3,722,665 3/1973 Probasco 198/184 German [73] A K b l d M FOREIGNPATENTS OR APPLICATIONS ss1gnee: a e-un eta werke 198 165Gutehofinungshutte 1,120,772 7/1968 Un1ted Kmgdom tt sgi HannoverPrimary ExaminerEvon C. Blunk y Assistant ExaminerDouglas D. Watts [22]Filed: July 16, 1973 Attorney, Agent, or FirmRalf H. Siegemund Appl.No.2 379,573

Foreign Application Priority Data July 14, 1972 Germany 2234631 US. Cl.198/165; 198/184; 226/95; 226/172 Int. Cl. B65G 15/14 Field of Search198/184, 165, 201; 271/197; 226/95, 172

References Cited UNITED STATES PATENTS 10/1949 Nebolsine 271/197 [5 7ABSTRACT Delicate elongated objects such as thin-walled tubing aremoved, i.e., withdrawn from processing equipment by means of coneyorbelts frictionally engaging such an object whereby additional lowpressure means suck the objects against the belts. These belts haveperforations and low pressure is applied to the back of the belts forsuction through these perforations, but they are covered outside of theback belt suction area. The belts are provided with soft, profiledridges, flanking the perforations to provide for a groove along whichthe object is sucked into engagement with the ridges.

9 Claims, 5 Drawing Figures US. Patent Oct. 28, 1975 Sheet 1 of 23,915,291

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APPARATUS FOR MOVING ELONGATED OBJECTS BACKGROUND OF THE INVENTION Thepresent invention relates to equipment for withdrawing and movingelongated objects which are rather sensitive to the application ofexternal pressure forces. More particularly, the invention relates toapparatus for moving and advancing elongated objects such as tubing bymeans of endless belts engaging such tubing frictionally.

Withdrawing and moving equipment of the caterpillar variety are used inthe art of manufacturing electric cables. This equipment includes twodriven endless belts frictionally engaging the cable and pulling thecable in the one direction of parallel movement of the two belts asfacing each other. The pulling force of this equipment can be increasedby decreasing the distance between the two belts so that the force offrictional engagement of the cable is increased. However, it is apparentthat the stronger such force, the more likely is any damage to thecable. This is particularly true if the outer shell or jacket of thecable is a thin wall tube. The same problem arises for moving any kingof thin-walled tubing.

SUMMARY OF THE INVENTION It is an object of the present invention toovercome the problem outlined above and to improve the withdrawalequipment for elongated objects such as thinwalled tubing or similarobjects, which require rather gentle handling, so that the surface isnot deformed, e.g., indented. I

It is another object of the present invention to improve withdrawingequipment using endless belts for engaging and moving such elongatedobjects.

In accordance with the preferred embodiment of the present invention, itis suggested to provide the belt or belts with many perforations and toprovide for suction through at least some of the perforations wherefacing the object to be moved. The pulling force and traction of thewithdrawing equipment is drastically increased in this manner withoutincreasing any compressing force as acting on the object due toengagement with the belts on opposite sides.

Preferably, suction pipes end in the back of the belts flanked bysealing belts, which are also disposed in the back of the respectivetransport belts for concentrating suction, and to limit leakage. Theperforations on the transport belts may be arranged in a row along thecenter of the respective belt and these perforations are flanked by softrubber ridges establishing a groove whose bottom has these perforations.These grooves are sealed at there ends and, as stated, the perforations,where not facing a suction pipe end, are sealed by supplementary beltsso that the suction power is effective in the groove where facing theobject to be engaged and as pulled by the transport belt. The ridgeelements have contour matching the contour of the object to be pulled.

Thus, it can be seen that in accordance with the invention, thetransport and withdrawing belt or belts are profiled to gently engagethe object to be moved. Such a profiled belt has a longitudinal groovein which low pressure is established for sucking the object against thesurface profile of the belt. The perforations are arranged in the bottomof the groove and suction is applied through them. The low pressuresource is stationary while the belt, of course, moves. Therefore,additional means are provided to seal the groove except for thoseperforations which face the suction equipment.

DESCRIPTION OF THE DRAWINGS While the specification concludes withclaims particularly pointing out and distinctly claiming the subjectmatter which is regarded as the invention, it is believed that theinvention, the objects and features of the invention and furtherobjects, features and advantages thereof will be better understood fromthe following description taken in connection with the accompanyingdrawings in which:

FIG. 1 is a side view of equipment for withdrawing elongated objects andimproved in accordance with the preferred embodiment of the presentinvention;

FIGS. 2, 3 and 4 are respectively section views along lines A-B; E-F andG-I-I in FIG. 1; and

FIG. 5 shows a section along line J-K in FIG. 4.

Proceeding now to the detailed description of the drawings, thewithdrawing equipment includes endless conveyor belts l and la eachlooping around drive pulleys, such as 2. Each belt is engaged by twopulleys. Pulleys pertaining to different belts but facing each other,are adjustable as to the distance between them so that the equipment canbe adjusted to the diameter of the object 3 to be pulled through the gapbetween and as defined by the disposition of the two belts.

The object 3 is, for example, a concentric tube system which includes aninner tube 14, an outer tube or jacket 15 polyurethane foam as thermalinsulation between the tubes; and a spacer helix 17, also made ofpolyurethane foam. The inner tube 14 may be made, for example, of copperwhile jacket 15 is a thin, longitudinally seam welded plastic foil.

Each belt is provided with many perforations 4.

These perforations are arranged along a central line of the belts so asto establish a row of perforations. These perforations pass flanged endsof suction pipes or tubes 5 having particularly suction openings andmouths which are flared in the plane that includes the direction ofadvance of the respective row of perforations. The suction tubes 5connect to a suction pump preferably via a manifold because a singlepump suffices. Ahead and behind each suction tube 5 are provided endlessbelts 10 which are looped around rolls or pulleys 9. One can see thatbelts 10 are quite closely disposed to suction tubes 5, 5a These belts10 engage the belts 1, la, so as to seal the perforations behind andahead of the suction. Actually, belts 10 are driven through frictionalengagement with belts 1, 1a Belts 1, la, each carry two soft and elasticridges 7 with arcshaped surface profile for engagement with the roundobject 3. The two ridges on each belt are arranged alongside therespective row of perforations and in symmetrical relation thereto.These two ridges establish a groove 8, open towards tubing 3 andextending for the entire length of the respective belt. Grooves 18 inridges 7 branch off the longitudinal groove 8 for increasing the areaavailable for suction.

Longitudinally extending elements 11 are affixed with one endrespectively to stationary support struc ture, while the respectiveother end extends into a groove 8. This way, grooves 8 are sealed tosome extent where the respective ridges 7 begin to support tube 3 aswell as where the ridges run off the tube. In other words, two elements11 seal a groove 8 from opposite ends so that the portion in'betweenserves as suction duct. The perforations in the bottom of this portionof the groove are either sealed by the belts 10 or face the opening ofthe suction mouth and pipe end 5. Suction causes the belts 10 to engagebelts 1 and la so as to enhence sealing.

Suction generally is quite strong and sealing of the various componentsis usually quite effective. Therefor, it may be advisable to providesome relief. The ridges of one of the belts, (e.g. on the left-hand sideof FIG. 4) could be covered with a gauze layer providing for some gasleakage. This way deformation of tubing 3, due to strong suction, isduly avoided. In this instance, rod-like sealing elements 11 cannot beused if, in fact, the gauze layer extends over the entire width ofgroove 8. That may not be too advantageous so that it is preferred touse a longitudinally split cover for the one groove (in lieu of a gauzelayer) which longitudinal cover could be made, for example, of solidwires or pins. Now sealing rods could be used as before.

As can be seen best in FIGS. 4 and 5, the suction pipe 5 has a flange 5awith upper and lower rails 5b as guides for the respective belts. Thesuction mouth of pipe 5 is flared in the direction belt advance andcircumscribed by a ridge 5c of length e and width b. Reference numeral5d refers to longitudinal slide ridges as support elements for thepassing belt. The ridges 5c and 5d leave a shallow space 13communicating with ducts to supply atmospheric pressure to the spacebetween ridges 5c and 5d. This way, slide friction of belt 1 or 1aacross the flange 5a is minimized and the complete width of therespective belt is not in friction contact with the entire suction tubeflange. One could provide a smoothing agent here in support of thisslide relief action which prevents binding of the belt.

It is important for practicing the invention that the friction betweenbelts 1, la, and tubing 3, is significantly higher than the frictionbetween belts 1, la and the suction mouth at the end face of pipe 5 asdefined by ridge 50. This difference in friction is readily availablethrough appropriate selection of materials. For example, belts 1, la canbe made of polyamide, pipe 5 is made of hard steel and ridges 7 are madeof a synthetic cell rubber with closed pores, such as moss rubber orother soft and flexible foam-like material with smooth surface. Thesuction area between the pipe ends 5 (suction mouth) as circumscribed byflange 5c and the belt around the perforation but as facing the suctionmouth is quite small while the effective suction area between tubing 3and belt is comparatively large. The groove 8 is instrumental here. Thisway, significant pulling and withdrawal force is provided while thefriction losses are quite small.

The invention is practiced, for example, in the following environment.German printed patent application No. 1,960,932 discloses a method formaking thermally insulated conduits. As stated, the conduit proper is acopper tube 14 about which has been wrapped an envelope, bylongitudinally folding a plastic ribbon. The space between envelope andconduit tube receives a spacer 17, and the remainder of that space isfilled with foam. The plastic ribbon is then seam welded along theadjoining edges' The apparatus described and constructed according tothe preferred embodiment of the invention can now be used to pull thetubing through the various tools participating in the envelope makingprocess. Thus, this withdrawal and moving equipment will be positionedbehind the welding station for the plastic ribbon. Since the pullingaction is a gentle one, this moving and withdrawing equipment can bedisposed rather closely to the welding station. At that point, the foammaterial may still be liquidous or just begins to fill the space betweenthe concentric tubes and/or may cure to become rigid.

The invention is not limited to the embodiments described above but allchanges and modifications thereof not constituting departures from thespirit and scope of the invention are intended to be included.

I claim:

1. In an apparatus for withdrawing and pulling elongated, thin wallcontinuous tubing with foam interior and being sensitive to localizedpressure, out of a production line, comprising two diagonally opposedend less conveyor belts frictionally engaging the tubing to be movedfrom opposite sides, the belts each having a plurality of perforationsfor applying suction to the tubing from opposite sides and including apulling load bearing portion and a soft-flexible portion eachsoftflexible portion having a round concave surface for engagement withthe tubing upon application of suction; and means including suctionpipes for providing suction pressure respectively to the rear of thebelts and to a portion of the perforations to be effected through theseperforations for sucking the tubing against the soft-flexible portion ofthe belt, so that the tubing is being withdrawn in uninterruptedsequence.

2. In an apparatus as in claim 1, the soft-flexible portions of the belteach having a groove, the respective perforations being arranged in thebottom of the groove.

3. In an apparatus as in claim 2, and including sealing belts in therear of the belt to seal perforations not facing the suction pipe ineach instance.

4. In an apparatus as in claim 2, the belt having branch groovescommunicating with said groove for increase the area effective forsuction of the object against the belt.

5. In an apparatus as in claim 2, and including a cover on the groovemade from material and construction for being permeable for gas.

6. In an apparatus as in claim 1, wherein the area of each belt directlyaffected by the suction pipe is smaller than the belt area in engagementwith the tubing.

7. In an apparatus as in claim 1, wherein the effect coeffcient offriction between the suction pipe and the load bearing portion of eachbelt is considerably lower than the effective coefficient of frictionbetween the soft-flexible portion of each belt and the tubing to bemoved.

8. In an apparatus as in claim 1, the suction pipe having a mouthlongitudinally flared in the direction of movement of the belt.

9. In an apparatus as in claim 1, wherein the perforations are in thepulling load bearing belt portion, the soft-flexible portion beingprovided by two ridges each with concave contour and a gap between theridges along the perforations, the concave contours for engagement withthe tube wall.

1. In an apparatus for withdrawing and pulling elongated, thin wallcontinuous tubing with foam interior and being sensitive to localizedpressure, out of a production line, comprising two diagonally opposedendless conveyor belts frictionally engaging the tubing to be moved fromopposite sides, the belts each having a plurality of perforations forapplying suction to the tubing from opposite sides and including apulling load bearing portion and a soft-flexible portion eachsoft-flexible portion having a round concave surface for engagement withthe tubing upon application of suction; and means including suctionpipes for providing suction pressure respectively to the rear of thebelts and to a portion of the perforations to be effected through theseperforations for sucking the tubing against the soft-flexible portion ofthe belt, so that the tubing is being withdrawn in uninterruptedsequence.
 2. In an apparatus as in claim 1, the soft-flexible portionsof the belt each having a groove, the respective perforations beingarranged in the bottom of the groove.
 3. In an apparatus as in claim 2,and including sealing belts in the rear of the belt to seal perforationsnot facing the suction pipe in each instance.
 4. In an apparatus as inclaim 2, the belt having branch grooves communicating with said groovefor increase the area effective for suction of the object against thebelt.
 5. In an apparatus as in claim 2, and including a cover on thegroove made from material and construction for being permeable for gas.6. In an apparatus as in claim 1, wherein the area of each belt directlyaffected by the suction pipe is smaller than the belt area in engagementwith the tubing.
 7. In an apparatus as in claim 1, wherein the effectcoeffcient of friction between the suction pipe and the load bearingportion of each belt is considerably lower than the effectivecoefficient of friction between the soft-flexible portion of each beltand the tubing to be moved.
 8. In an apparatus as in claim 1, thesuction pipe having a mouth longitudinally flared in the direction ofmovement of the belt.
 9. In an apparatus as in claim 1, wherein theperforations are in the pulling load bearing belt portion, thesoft-flexible portion being provided by two ridges each with concavecontour and a gap between the ridges along the perforations, the concavecontours for engagement with the tube wall.